Supplementary Material for: Patterns of Sensitization to Inhalant Allergens in Japanese Lower-Grade Schoolchildren and Related Factors

Objective: This study clarified sensitization patterns to house dust mite (HDM) and Japanese cedar pollen (JCP) in Japanese lower-grade schoolchildren. We also explored factors associated with allergic sensitization. Methods: This cross-sectional study used a database from the Study on Respiratory Disease and Automobile Exhaust (SORA), a Japanese health study project. The subjects comprised 8,815 pupils aged 6-9 years. We obtained the distribution of HDM- and JCP-specific IgE, respectively, as a marker of sensitization. To determine factors associated with sensitization, we used logistic regression and calculated adjusted odds ratios (AORs) for the relative prevalence of sensitization. The cut-off point for specific IgE levels was 0.35 kU/l. Results: Sensitization to HDM and JCP was detected in 51 and 39% of subjects, respectively, occurring more often in boys and at older ages. In addition, AORs of sensitization to HDM/JCP were higher in subjects with a history of bronchitis, parental asthma, parental atopic eczema and parental pollinosis. In contrast, AORs for sensitization were lower in those subjected to maternal passive smoking as well as among boys with pets. AORs of sensitization to JCP alone were lower in those with a history of otitis media, those who had been bottle milk fed, and those who were not the firstborn and who lived near a busy road. Conclusion: Sensitization to HDM and JCP was detected in 51 and 39% of lower-grade schoolchildren, respectively.研究目的：本研究明确了日本低年级学龄儿童对屋尘螨（house dust mite, HDM）与日本柳杉花粉（Japanese cedar pollen, JCP）的致敏模式，并探讨了与过敏性致敏相关的影响因素。 研究方法：本研究为横断面研究，采用日本呼吸疾病与汽车尾气研究（Study on Respiratory Disease and Automobile Exhaust, SORA）项目的数据库。研究对象共计8815名6~9岁的小学生。我们分别获取了作为致敏标志物的屋尘螨和日本柳杉花粉特异性免疫球蛋白E（immunoglobulin E, IgE）的分布特征。为明确与致敏相关的影响因素，本研究采用logistic回归分析，计算了致敏相对患病率的校正比值比（adjusted odds ratios, AORs）。特异性IgE水平的截断值设定为0.35 kU/l。 研究结果：分别有51%和39%的研究对象检出屋尘螨与日本柳杉花粉致敏，且该致敏现象在男性儿童及年龄较大的儿童中更为高发。此外，既往存在支气管炎病史、父母罹患哮喘、父母特应性皮炎以及父母花粉症的研究对象，其屋尘螨/日本柳杉花粉致敏的校正比值比更高。与之相反，存在母亲被动吸烟暴露史的儿童以及家中饲养宠物的男性儿童，其致敏的校正比值比更低。仅对日本柳杉花粉致敏的研究对象中，既往有中耳炎病史、曾接受奶瓶喂养、非头胎以及居住于繁忙道路附近者，其致敏的校正比值比更低。 研究结论：本研究显示，分别有51%和39%的低年级学龄儿童检出屋尘螨及日本柳杉花粉致敏。